Browse Prior Art Database

Priority Data Transfer System

IP.com Disclosure Number: IPCOM000079866D
Original Publication Date: 1973-Sep-01
Included in the Prior Art Database: 2005-Feb-26
Document File: 2 page(s) / 21K

Publishing Venue

IBM

Related People

Ouchi, NK: AUTHOR

Abstract

A data-storage system is shown which comprises a control unit 1 for controlling information transfer between storage unit 2, storage unit 3 and a CPU. Storage unit 2 has a data rate which is slower than the data rate of storage unit 3.

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Priority Data Transfer System

A data-storage system is shown which comprises a control unit 1 for controlling information transfer between storage unit 2, storage unit 3 and a CPU. Storage unit 2 has a data rate which is slower than the data rate of storage unit
3.

Control unit 1 can transfer information from storage unit 2 to storage unit 3. However, due to the difference in data rate between storage unit 2 and storage unit 3, the information is buffered within control unit 1. During the period of time that information is being read into the buffer in control unit 1 from storage unit 2 or being read out of the buffer in control unit 1 to storage unit 2, the control unit allows the CPU to be connected to storage unit 3. In order to make up for the delay in transfer of data to or from storage unit 2 to or from storage unit 3, storage unit 2 is given priority over the CPU. Under these conditions, when storage unit 2 has either completed filling the buffer within the control unit or has completed emptying the buffer, it will present an interrupt to the control unit 1. Thus the control unit will cease its operation with the CPU and service the storage unit 2 with respect to its actions with storage unit 3.

In such a manner, the most efficient use is made of communications between storage unit 2 and storage unit 3, and between the CPU and storage unit 3.

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